Biodiversity and Invasive Plant Species-

A workshop I attended earlier this week, Weed Watchers, provided inspiration for this week’s UNLESS… Earth-Friendly Chroniclers’ challenge. We learned about invasive plants that threaten the native plant and animal communities in the Tualatin River watershed where I live.

Biodiversity is at risk when invasive plants get in the way of the native plants that do a better job:

keeping soil in place and out of rivers,

soaking up excess nutrients from fertilizers,

providing shade to keep water temperatures cool for fish,

providing somewhere for native animals to live, and

providing food sources year round for pollinators and native animals.

Our instructor called invasive plants “bullies” because of their ability to crowd out the beneficial native plants that are vital for the health of native life forms and ecosystems.

On Kangaroo Island, South Australia, our weed problems are much less than on the nearby mainland because we have 40 per cent native vegetation, much of it in very large blocks. But unfortunately we still do have many aggressive weeds such as Bridal Creeper and other Asparagus weeds, African Boxthorn and Watsonia, and many people who want to grow ‘pretty’ gardens with potential weeds. My friend Veronica who runs the local native plant nursery says that finding out about the pervasiveness of weeds has changed her life forever. She used to enjoy the great outdoors and admire ‘pretty plants’. Now she sees weeds almost everywhere. True for me too.

Our instructor at the Weed Watcher class cautioned us, that we would see nature in those terms,too. I must say that I agree, once a person has awareness of the invasive plants, it would be difficult to ignore them. (My hands are sore after spending most days last week pulling invasives out of the riparian zone of our wetland. For the time being its a tremendous reward to see the native plants again!)

Thank you for describing the situation in your region of Australia. Are ther programs to encourage invasive removal and restoration?

Christine~
It seems your job is both rewarding and at the same time frustrating. Wonderful that you can help to monitor and map. Good to see that countries are working together to promote public awareness and action.Frustrating not to have all the manpower and monetary support. That is probably the case in many parts of the world. Although, Liz wrote about the Department of Environment in South Africa working to properly clear and replant, and- at the same time, create jobs and poverty alleviation through their program of environmental conservation initiatives. That sounds like a good model – potentially a win/win situation for the environment, resource preservation, and economy.http://natureontheedge.com/2015/05/03/unlessearth-friendly-chroniclers-challenge-9-invasive-plants/
~Jane

Lola Jane- it is shocking to see how intensely the Ice Plant has spread and is spreading in California. I’ve seen it for sale as a garden plant here, and in Arizona. Seeing the potential for how invasive and destructive it can be, it would seem responsible and reasonable to expect some nursery stock to come with warning or caution labels. I suspect many people are completely unaware …
~Jane

I am really surprised that this plant is still sold in Oregon, and in Arizona. I think a warning or caution label is a minimum requirement.

There is a less invasive variety (Carpobrotus chilensis) but because they are so similar, it can easily crowd out native plants as well. Why take a chance, and then be faced with the clean up afterwards, as what will need to be done here in our Central Coast.

At the very least, I hope garden centers / government agencies / BLM / invasive plant experts are communicating closely and monitoring these potentially invasive plants, especially knowing what we now know about their spread, and how it affects our fragile ecosystem.

Oh dear… your reaction of surprise is causing me to double-think my statement. I based it on past season experiences. Now, I think I better double check to see if those plants are currently still available. Thank you for keeping me on my toes! 🙂

However, all in the landscaping/garden businesses should be knowledgeable about the implications of all that is sold on the garden/landscaping market from plants to chemicals to wild bird/animal food products.

Lola Jane-
You aren’t kidding when you describe the Yellow Starthistle as a very aggressive plant! It is a problem in Southern Oregon in the Medford area and out in Northeast Oregon along the Columbia/ Snake River area.

I can see why it is placed on the Early Detection/ Rapid Response list for my area- the Tualatin River watershed.

I admire how your Department of Environment is working to properly clear and replant, and- at the same time, create jobs and poverty alleviation through their program of environmental conservation initiatives. That sounds like a good model – potentially a win/win situation for the environment, resource preservation, and economy.

Your quote from the impact abstract mirrors what the facilitators at the workshop I attended recently were saying about some of the devastating impacts non-native “plant bullies” can have on watersheds and biodiversity of ecosystems.

We are all connected in this problem… thank you for giving a window for us to see how invasive plants affect your area of South Africa.
~Jane